package 笔试.秋招2023.数科360.T1;

import java.util.Scanner;

/**
 * 判断字符串是否为回文
 *
 * @author 张从龙
 * @version [1.0.0, 2022/8/27]
 */
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String str = scanner.next();
        int length = str.length();

        //定义头尾指针
        for (int i = 0; i < length / 2; i++) {
            if (str.toCharArray()[i] != str.toCharArray()[length - i - 1]) {
                System.out.println("NO");
                return;
            }
        }

        System.out.println("YES");
    }
}